Capacitors are used as part of integrated circuits as analog components or, for example, as memory cells in digital circuits. It is well known from basic physics that for a capacitor the capacitance is proportional to the product of the area of the electrodes and the dielectric constant .epsilon., and inversely proportional to the thickness t of the dielectric. With increasing reduction in scale of semiconductor devices, the minimum physical size of the capacitors required to provide the necessary capacitance becomes a limiting factor.
It has been proposed to increase the size of the electrodes by varying their shape. It has also been proposed to increase the dielectric constant of the dielectric material. Typically, silicon dioxide is used as the dielectric, and this has been replaced by tantalum oxide (Ta.sub.2 O.sub.5), which is actually known to have a high dielectric constant. The formation of a tantalum oxide dielectric is a complicated process involving multiple steps and tool changes.
An object of the invention is to provide a simple process for producing small dimension, high capacitance capacitors on semiconductor devices.